Platform for deploying web-based privacy-preserving data surveys using secure multi-party computation (MPC).
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Implementation of a web-based data collection and aggregation infrastructure that utilizes secure multi-party computation techniques to allow individual contributors to submit their data without revealing it to the other participants.


It is expected that this application will operate on an Amazon Web Services EC2 instance running Amazon Linux under a security group that permits connections on port 80. The environment in which it runs is set up as follows.

  • First, install Node.js, MongoDB, and necessary modules:
yum -y update
yum -y install nodejs npm --enablerepo=epel
echo "[MongoDB]
name=MongoDB Repository
enabled=1" | sudo tee -a /etc/yum.repos.d/mongodb.repo
yum install -y gcc-c++ mongodb-org-server mongodb-org-shell mongodb-org-tools`
  • Navigate to the server/ directory, install the NPM dependencies, and install the global dependency:
npm install
npm install -g forever
  • Next, set up the database file and start the MongoDB server:
mkdir -p /data/db
  • Finally, retrieve the application files and in the directory "server/" run:
export NODE_ENV=production
authbind --deep forever -o log.txt -e error.txt start index.js

Local machine installation

Instructions for setting up the environment on a Mac OS X or Linux local machine.

  • Make sure to have Node.js and MongoDB installed.
  • Navigate to the server/ directory and install the NPM dependencies:
npm install
  • Now install the global dependency:
npm install -g forever
  • Create the database file:
mkdir -p /data/db
  • Start the MongoDB server:
  • Open a new terminal tab or window and navigate back to the server/ directory if you are not already there.

Non-production testing

  • For testing, start the Node.js server with no environment variables:
node index.js

Production release

  • For production, start the Node.js server with a production environment variable:
export NODE_ENV=production
node index.js
  • Open up the browser and navigate to "localhost:8080"

Application usage

Instructions on how to operate the web-mpc application. All steps below are performed in the browser.

Generate session key

  • Navigate to localhost:8080/create.
  • Click on Generate Session and copy and share the session key with all participants.

Fill out data

  • All participants will navigate to localhost:8080, paste the session key into its designated field and proceed to fill out the information. Once completed, click Submit.

Manage session

  • Navigate to localhost:8080/manage.
  • Input your session key and password.
  • Generate participation links.
  • Start the session.

Retrieve the result

  • Stop the session
  • Navigate to localhost:8080/unmask.
  • Paste the session key and password in its designated fields.
  • Click Browse and upload the private key file that was downloaded when generating the session key.
  • Click Unmask Data and view the result.


Web-mpc is freely distributable under the terms of the MIT license. This release supports Handsontable's "Nested headers", a Pro feature. A valid license must be obtained when using this feature.